The title of the webpage, can be changed if you login as admin, and then go to Site Settings → Project name. Change the name, and click on Save.
Go to your project and login as admin. In the settings page, you will be able to change the project logo and the default images for the menu items and the cover image in the restaurant menu.
If you go to this folder app/Notifications
There are list of PHP files that represent the content of the email And inside them, there is function called toMail
You can modify the strings there.
If you want to change the layout, ex, include some CSS for the email you can edit the blade file here resources/views/vendor/notifications/email.blade.php